Deciphering the long-term performance and underlying mechanisms of an engineering-scale anaerobic-anoxic-oxic-anaerobic-vibrating MBR process

Abstract

This study presents a comprehensive evaluation of an engineering-scale (75000 m³/d) anaerobic-anoxic-oxic-anoxic with vibrating membrane bioreactor (AAOA-VMBR) system for municipal wastewater treatment. By integrating mechanical reciprocation as the primary fouling control strategy, the system demonstrated exceptional operational stability and treatment efficiency over a 20-month monitoring period. Structural stress analysis confirmed the mechanical reliability of the large-scale vibrating equipment, with all critical components operating within safe stress limits. The system achieved remarkable pollutant removal efficiencies, exceeding 95% for COD, NH₃-N and TP, and 87% for TN, supported by a specialized microbial community enriched with denitrifying phosphate-accumulating organisms for simultaneous nitrogen and phosphorus removal. The VMBR exhibited enhanced fouling control, maintaining a stable flux of 16.5 LMH with an average fouling rate of only 0.045 kPa/d. A key achievement was the significant reduction in energy consumption, with the specific energy for membrane fouling control as low as 0.035 kWh/m³, which is 65%–82% lower than conventional aerated MBRs. Despite these successes, spatial heterogeneity in foulant deposition highlighted the need for optimized hydrodynamics in future designs. These findings validate the AAOA-VMBR system as a sustainable, energy-efficient technology for wastewater treatment.

Graphical abstract

Keywords

Membrane bioreactor (MBR) / Membrane fouling / Wastewater treatment / Mechanical vibrating / Fouling control

Highlight

	● This study validates the mechanical reliability of an engineering-scale VMBR.
	● AAOA-VMBR system achieves > 95% COD, NH3-N and TP removal and 87% TN removal.
	● VMBR enables enhanced fouling control with stable flux and low fouling rate.
	● Specific energy for membrane fouling control reaches a low value of 0.035 kWh/m3.

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